Process for producing foundry exothermic body

Abstract

A process for producing a foundry exothermic body such as an foundry exothermic riser sleeve includes the steps of preparing a raw material mixture whose components include one or more powdered/granular refractories, one or more powdered/granular exothermic materials, one or more powdered/granular oxidants and one or more powdered pro-oxidants, mixing thermosetting phenol resin with the raw material mixture to coat grain surfaces of the raw material mixture with thermosetting phenol resin and obtain a thermosetting phenol resin coated raw material mixture, and using the shell molding process to form and cure the thermosetting phenol resin coated raw material mixture into a foundry exothermic body of prescribed shape.

What is claimed is: 
     
       1. A process for producing a foundry exothermic shaped body comprising the steps of: preparing a raw material mixture whose components include one or more powdered/granular refractories, one or more powdered/granular exothermic materials, one or more powdered/granular oxidants and one or more powdered pro-oxidants,   mixing a thermosetting phenol resin with the raw material mixture to coat grain surfaces of the raw material mixture with the thermosetting phenol resin and obtain a thermosetting phenol resin coated raw material mixture, and   using a shell molding process to form and cure the thermosetting phenol resin coated raw material mixture into a foundry exothermic shaped body.   
     
     
       2. A process according to claim 1, wherein coating of grain surfaces of the raw material mixture with the thermosetting phenol resin is effected at a temperature between normal room temperature and 160° C. 
     
     
       3. A process according to claim 2, wherein the foundry exothermic shaped body is an exothermic riser sleeve, an exothermic core, an exothermic neckdown core, an exothermic mold, or an exothermic pad. 
     
     
       4. A process according to claim 1, wherein the foundry exothermic body is an exothermic shaped riser sleeve, an exothermic core, an exothermic neckdown core, an exothermic mold, or an exothermic pad. 
     
     
       5. A process for producing a foundry exothermic shaped body from a raw material which components include one or more powdered/granular refractories, one or more powdered/granular exothermic materials and one or more powdered/granular oxidants comprising the steps of: dividing the components for preparing the raw material mixture into a primary raw material mixture of components that do not undergo an exothermic or a combustion reaction when heated to a temperature of 130-300° C. and a secondary raw material mixture components consisting of components other than the primary raw material mixture components,   mixing a thermosetting phenol resin with the primary raw material mixture components at a temperature of 130-160° C. to coat grain surfaces of the primary raw material mixture components with a molten thermosetting phenol resin layer,   mixing a liquid thermosetting phenol resin with the secondary raw material mixture components at normal room temperature or a temperature exceeding normal room temperature but not exceeding 130° C. to coat grain surfaces of the secondary raw material mixture components with the liquid thermosetting phenol resin, and   mixing the thermosetting phenol resin coated primary and secondary raw material mixture components, and   using a shell molding process to form and cure the obtained thermosetting phenol resin coated raw material mixture into a foundry exothermic shaped body.   
     
     
       6. A process according to claim 5, wherein the foundry exothermic shaped body is an exothermic riser sleeve, an exothermic core, an exothermic neckdown core, an exothermic mold, or an exothermic pad. 
     
     
       7. A process for producing a foundry exothermic shaped body comprising the steps of: preparing a mixture comprising 60-70 wt % of one or more powdered/granular refractories, 15-30 wt % of one or more powdered/granular exothermic materials and 5-15 wt % of one or more powdered/granular oxidants,   adding to 100 parts of the mixture 1-5 parts of thermosetting phenol a resin together with resin setting agent followed by mixing at 130-160° C. to coat grain surfaces of the mixture with a molten thermosetting phenol resin layer and obtain a thermosetting phenol resin coated mixture, and   using a shell molding process to form and cure the thermosetting phenol resin coated mixture into a foundry exothermic shaped body.   
     
     
       8. A process according to claim 7, wherein the foundry exothermic shaped body is an exothermic riser sleeve, an exothermic core, an exothermic neckdown core, an exothermic mold, or an exothermic pad. 
     
     
       9. A process for producing a foundry exothermic shaped body comprising the steps of: preparing a mixture comprising 60-70 wt % of one or more powdered/granular refractories, 15-30 wt % of one or more powdered/granular exothermic materials and 5-15 wt % of one or more powdered/granular oxidants,   adding to 100 parts of the mixture 1-5 parts of a thermosetting phenol resin together with a resin curing agent followed by mixing at 130-160° C. to coat grain surfaces of the mixture with a molten thermosetting phenol resin layer and obtain a thermosetting phenol resin coated mixture,   adding to 100 parts of the thermosetting phenol resin coated mixture 10-20 parts of a thermosetting phenol resin coated mixture obtained by mixing, at normal room temperature or a temperature exceeding normal room temperature but not exceeding 130° C., 1-6 wt % of liquid or powdered phenol resin, 10-30 wt % of one or more powdered oxidants, 60-75 wt % of one or more finely powdered pro-oxidants and 8-15 wt % of one or more finely powdered exothermic agents, and   using a shell molding process to form and cure the resulting mixture into a foundry exothermic shaped body.   
     
     
       10. A process according to claim 9, wherein the foundry exothermic shaped body is an exothermic riser sleeve, an exothermic core, an exothermic neckdown core, an exothermic mold, or an exothermic pad.